Method for excavating hole and apparatus therefor

ABSTRACT

A method for excavating a hole and an apparatus therefor are suitable for the operation of excavating a hole used for laying a lateral sewer or mounting pipe, which extends from a main sewer pipe (10) toward the ground surface, on the main sewer pipe. The method comprises the step of rotating a rod (12) about its axis in a space provided in the ground (72) while advancing the rod in the direction of penetrating a wall member (10) defining the space, and the step of utilizing the advanced rod for a guide while excavating a hole in the ground from the tip side of the rod toward the space. The apparatus embodying the method described above comprises a rod propelling machine (14) disposed in a space provided in the ground (72) and for rotating a rod (12) about its axis while advancing the rod and an excavating machine (74) utilizing the advanced rod for a guide and for excavating a hole in the ground from the tip side of the rod toward the space, wherein the rod propelling machine (14) includes operating means (21) for rotating the rod about its axis while advancing the rod and means (59) placed in front of the operating means and for guiding the rod in the direction of penetrating a wall member defining the space. Therefore, the hole is easily accurately excavated even in a spot incapable of being excavated by a driving method.

BACKGROUND OF THE INVENTION

1. Field of the Invention:

This invention relates to a method for excavating a hole in the groundand an apparatus therefor and, more particularly, to a method and anapparatus suitable for the operation of excavating a hole used forlaying a lateral sewer or mounting pipe, which extends from a main sewerpipe toward the surface of the ground, on the main sewer pipe.

2. Description of the Prior Art:

One method for laying a branch pipe or mounting pipe for sewage thecomprises the steps of excavating a ditch by the open cut method,positioning the mounting pipe in the excavated ditch and then connectingthe mounting pipe to a main pipe provided in the ground. The methodnoted above, however, cannot be applied to locations which cannot beexcavated by the open cut method.

A different method for laying a sewage mounting pipe comprises the stepsof excavating a hole from the ground surface to the main pipe by anexcavating machine such as an earth auger and then positioning themounting pipe in the hole. According to this method, however, the holeis formed by excavating the ground from the ground surface to the mainpipe provided in the ground, so that the tip of the excavated hole oftendeviates from the position where the main pipe is embedded and, as aresult, the mounting pipe cannot be accurately laid.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method for excavatinga hole and an apparatus therefor, which can easily and accuratelyexcavate a hole even in a location incapable of being excavated by anopen cut method.

A method for excavating a hole according to the present inventioncomprises the step of rotating a rod about its axis in a space providedin the ground while advancing the rod to penetrate a wall memberdefining the space and the step of utilizing the advanced rod as a guidewhile excavating a hole in the ground from the tip end of the rod towardthe space.

An apparatus for excavating a hole according to the present inventioncomprises a rod propelling machine disposed in a space provided in theground and for rotating the rod about its axis while advancing the rodand an excavating machine utilizing the advanced rod as a guide whileexcavating a hole in the ground from the tip side of the rod toward thespace, wherein the rod propelling machine is provided with operatingmeans for rotating the rod about its axis while advancing the rod androd guiding means placed in front of the operating means and for guidingthe rod in the direction of penetrating a wall member defining thespace.

The rod propelling machine comprises operating means for clamping therod and rotating the rod about its axis while advancing the rod, meansfor guiding the rod along a curved path and means for supporting theoperating means and guide means.

The excavating machine according to the present invention utilizes therod extending from the space provided in the ground as a guide whileexcavating a hole in the ground from the tip end of the rod toward thespace, and comprises means for clamping the tip of the rod, excavatingmeans disposed coaxially with the rod to extend along the rod, drivemeans for rotating the excavating means around the rod while advancingthe excavating means along the rod and means for supporting the clampingmeans, excavating means and drive means.

According to the present invention, since a hole is excavated from thetip end of the rod toward the space while utilizing the rod extendingfrom the space provided in the ground as a guide, it is possible toexcavate the hole accurately and easily even in locations incapable ofbeing excavated by the driving method.

According to the apparatus for excavating a hole of the presentinvention, the rotated and advanced rod is guided in the direction ofpenetrating the wall member defining the space. Therefore, when thespace is elongated like a pipeline, the hole can be excavated so as toextend in the direction intersecting the extending direction of thespace.

According to the rod propelling machine of the present invention, sincethe guide means guides the rod along the curved path, the guide meansdoes not hinder the rotation and advance of the rod.

According to the excavating machine of the present invention, since theexcavating means is advanced along the rod while being clamped to therod, the hole can be excavated accurately.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects and features of the invention willbecome apparent from the following description of a preferred embodimentof the invention with reference to the accompanying drawings, in which:

FIG. 1 is a front view showing an embodiment of a rod propeller used inthe present invention;

FIG. 2 is a enlarged-scale plan view showing a portion of an operatingmechanism of the rod propelling machine shown in FIG. 1;

FIG. 3 is an enlarged-scale sectional view taken along the line 3--3 inFIG. 1;

FIG. 4 is an enlarged-scale sectional view taken along the line 4--4 inFIG. 1;

FIG. 5 is an enlarged-scale sectional view taken along the line 5--5 inFIG. 1;

FIG. 6 is a sectional view showing an embodiment of a guide mechanismused in the rod propeller shown in FIG. 1;

FIG. 7 is a sectional view taken along the line 7--7 in FIG. 6;

FIG. 8 is a view for explaining a process until a mounting pipe ispositioned;

FIG. 9 is a front view showing an embodiment of an excavating machineused in the present invention; and

FIG. 10 is an enlarged-scale view showing the excavating machine underthe final process of excavation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a rod propelling machine or rod propeller 14 forrotating a flexible rod 12 such as an oil-tempered wire about its axiswhile advancing the same is disposed in a main sewer pipe 10 embedded inthe ground. The rod propeller 14 comprises a support mechanism 15 forsupporting respective mechanisms of the rod propeller.

The support mechanism 15 is provided with a base member 16 extendingalong the main pipe 10 and a plurality of jacks 18 disposed in spotslongitudinally spaced apart from each other on the base member 16 so asto maintain the base member 16 in a fixed state relative to the mainpipe 10. The jacks 18 are disposed at positions angularly spaced apartfrom each other about the axis of the main pipe 10 and extend radiallyof the main pipe 10. On the tip of a rod of each jack 18 is mounted apad 20 pressed against the inner surface of the main pipe 10 when thejack is expanded.

An operating mechanism 21 for rotating the rod 12 about its axis whileadvancing the same is supported by the base member 16. As shown in FIGS.1 to 5, the operating mechanism 21 is provided with a pair of rodlikeguides 22 extending backwardly along the rod 12 in the main pipe 10 fromthe rear end of the base member 16 so that they are parallel with eachother. The tip of each guide 22 is secured to the base member 16 by anut 24. The rear end of each guide 22 is secured by a nut 28 to aconnecting piece 26 for interconnecting both guides 22 so as to preventtheir relative positional relationship from changing.

A slider 30 of the operating mechanism 21 is supported by the guides 22so as to be slidable along the guides 22. The slider 30 has throughholes for slidably receiving the guides 22 and is connected to a jackfor moving slides 30 back and forth the along the guides 22. A cylinderof the jack 32 is secured to the connecting piece 26 so as to extendbackwardly from the slider 30. A rod of the jack 32 is secured to theslider 30 by a nut 34.

As shown in FIGS. 2 and 3, the slider 30 is provided with a space whichextends through the slider 30 along the rod 12. In the space of theslider 30 is disposed a chuck 36 of the operating mechanism 21 so thatthe chuck is rotatable about the axis of the rod 12 while being clampedto the rod. A chuck body 38 of the chuck 36 is rotatably supported bythe slider 30 through a plurality of bearings 40.

The chuck body 38 is provided with a through hole for slidably receivingthe rod 12. The tip of the through hole is a hole of such a small boreas to form a slight gap between the chuck body 38 and the rod 12. On thecontrary, a central portion of the through hole constitutes a spacelarger than the hole of the small bore. Also, the rear end of thethrough hole constitutes a conical space. In the conical space at therear end of the through hole are disposed a plurality of clamping claws42 movable along the rod 12.

As seen in FIG. 3, the respective claws 42 are subjected to force forprotruding the claws 42 from the central space, i.e., force forreleasing the rod 12 from the clamping claws 42, by a coiled spring 44disposed in the central space. Also, a cylinder mechanism 46 foradvancing the respective claws 42 relative to the chuck body 38 issupported by the chuck body 38.

The slider 30 supports a motor 48 for rotating the chuck body 38. Asshown in FIGS. 1 and 2, rotation of the motor 48 is transmitted to thechuck body 38 through a gear-like timing pulley 50 mounted on the rotaryshaft of the motor 48, a timing belt 52 trained over the timing pulley50 and a timing pulley 54 provided on the chuck body 38 to mesh with thetiming belt 52.

As shown in FIG. 3, the rod 12 extends rotatably slidably through thecylinder mechanism 46. Thus, the cylinder mechanism 46 is provided witha plurality of bearings 56 for receiving rotatably slidable rod 12. Thechuck body 38 is also provided with a bearing 58 for receiving rotatablyslidably rod 12.

The base member 16 supports a guide mechanism 59 for guiding rod 12along the curved path. The rod is rotated by the operating mechanism 21while being drawn out along the axis of the main pipe 10.

As shown in FIGS. 6 and 7, the guide mechanism 59 is provided with aplurality of bearings 60 which are respectively fitted in holes bored inthe central portions of square plates 62. Also, the respective bearings60 are sequentially disposed between spacers 64 so that the rotarycenters of the bearings are disposed along a curve having apredetermined radius of curvature. Each plate 62 and spacer 64 isinterconnected fixedly to each other by a plurality of bolts 66extending along the curved paths. In the adjacent bearings 60 arerespectively fitted rings 68, through which the rod 12 extends rotatablyslidably.

At the time of propelling the rod, the rod 12 is passed from theoperating mechanism 21 to the guide mechanism 59 and a drill 70 ismounted on the tip of the rod 12.

Then, the rod propeller 14 is disposed in a predetermined spot in themain pipe 10 by pushing the rod propeller 14 by a predetermined distancefrom one vertical shaft or manhole communicating to the main pipe 10 tothe other, or by inserting a wire extending from one manhole to theother into the main pipe 10, connecting the rod propeller 14 to one endof the wire and then drawing the wire toward the other end thereof by apredetermined length.

Next, the rod propeller 14 is secured to the main pipe 10 by expandingthe jacks 18 to the support mechanism 15. Subsequently, the motor 48 isrotated, and the jack 32 is repetitively expanded and contracted insynchronism with the operation of the cylinder mechanism 46. That is,the cylinder mechanism 46 is expanded while the jack 32 is expanded, andthe cylinder mechanism 46 is contracted while the jack 32 is contracted.

Accordingly, the slider 30 reciprocates back and forth. Also, the chuck36 reciprocates back and forth along with reciprocation of the slider30. Further, the chuck 36 clamps the rod 12 at the time of advancing andreleases the rod 12 at the time of retreating.

As a result, the rod 12 repeats intermittently the process of rotatingabout its axis while advancing. By so doing, the rod 12 penetrates thewall member of the main pipe 10 so as to be propelled toward the groundsurface. As shown in FIG. 8(A), the tip of the rod 12 finally projectsupward from the ground surface 72. The rod 12 can be advanced straightthrough its rotation with high speed.

As shown in FIG. 9, an excavating machine 74 is installed on the ground,which utilizes the rod 12 extending from the main pipe 10 as a guidewhile excavating a hole from the tip side of the rod 12 toward the mainpipe 10.

The excavating machine 74 comprises a chuck 78 fixed to the upperportion of a support bed 76 so as to releasably clamp the tip of the rod12 protruding above on the ground. The support bed 76 supports a slider80 to be movable parallel to the rod 12. The slider 80 is moved by acylinder mechanism 82 mounted on the support bed 76.

An excavating mechanism 84 for drilling a hole along the rod 12 isremovably mounted on the slider 80 by fittings 86, 88. The excavatingmechanism 84 in the embodiment shown in the drawing is an earth augerprovided with a tubular casing 90, a screw conveyer 92 receivedrotatably in the casing and a cutter 94 mounted on the tip of the screwconveyer. However, a different type of excavating mechanism may beapplied to the present invention.

As clearly shown in FIG. 10, a shaft 96 of the screw conveyer 92 has athrough hole 98 extending through the shaft 96 along the axis thereof soas to rotatably receive rod 12. Also, the lower end of the through hole98 constitutes a small hole, through which the rod 12 passes andcommunicates to the outside through a plurality of holes 100 extendingradially about shaft 96.

As seen in FIG. 9, the casing 90 and the shaft 96 are supportedrotatably about the axis of the rod 12 by fittings 86 and 88,respectively. Also, the rotation of a motor 102 supported by the supportbed 76 is transmitted through a chain 104 to the shaft 96.

In excavation, after the tip of the rod 12 is first inserted into thehole 98 of the excavating machine 84, the tip of the rod 12 is clampedby the chuck 78 so as to tension the rod 12. At this time, the chuck 36of the rod propeller 14 is operated to clamp the rod 12.

In this state, the motor 102 is operated and the cylinder mechanism 82is expanded. Accordingly, when the screw conveyer 92 is rotated aboutthe axis of the rod 12 while being advanced, the casing 90 is advancedtogether with the screw conveyer 92. As shown in FIG. 8(B), theexcavating mechanism 84 is then advanced along the rod 12 and finallythe tip of the excavating mechanism 84 reaches the main pipe 10 as shownin FIG. 8(C) and FIG. 10. Consequently, a portion of the wall of themain pipe 10 is cut off by the cutter 94.

The hole excavated as above mentioned reaches accurately to the mainpipe 10 since the excavating mechanism 84 is advanced by the guidance ofthe rod 12. Therefore, the accurate hole can be easily excavated.

In laying the mounting pipe, a cap 106 is first mounted on the upper endof the shaft 96 to close the hole 98 of the shaft 96 at the upper end ofthe shaft 96. As shown in FIG. 9, the cap 106 may be mounted before theexcavation. The cap 106 has a nipple 108 communicating to the hole 98 inthe shaft 96.

Next, as shown in FIG. 8(C), a hose 110 is connected to the nipple 108and seal agent 112 is poured from the hose 110. As shown in FIG. 10, theseal agent 112 flows out of the hole 98 through the holes 100 to close agap between the casing 90 and the main pipe 10.

Then, after the screw conveyer 92 is removed together with cut pieces114 of the main pipe 10, as shown in FIGS. 8(D) and 10, the lateralsewer or mounting pipe 116 is inserted into the casing 90 until the tipof the mounting pipe 116 is fitted in a hole 118 bored in the main pipe10. The mounting pipe 116 may be inserted either manually ormechanically.

Thereafter, the chuck of the excavating machine 74 releases the rod 12.Then, the rod 12 is drawn back by the rod propeller 14, and the rodpropeller 14 is removed. The rod 12 can be drawn back by the operatingmechanism 21 of the rod propeller 14. In particular, the rod 12 can bedrawn back by repeating the process of drawing back the claws 42 whileclamping the rod 12, and advancing the claws 42 while releasing the rod12.

Next, as shown in FIG. 8(E), seal agent 120 is poured from a thin pipe122 into the outer periphery of the bottom of the mounting pipe 116, andthen the casing 90 is removed. After the removal of the casing 90, earthand sand are poured into the gap between the casing 90 and the mountingpipe 116. Thus, the mounting pipe 116 is stabilized.

Further, the present invention can be applied not only to the method andapparatus for excavating holes used for laying a mounting pipe 116, butalso for example, to a method and apparatus for excavating holes usedfor laying a pipe extending from one shaft to another shaft and holesfor other purpose.

What is claimed is:
 1. An excavating machine utilizing a rod having atip end portion extending from a space provided in the ground so as toact as a guide while excavating a hole from the tip end portion of saidrod toward said space, comprising:means located at the tip end portionfor clamping the tip end portion of said rod; excavating means disposedcoaxially about said rod so as to advance toward said space along saidrod; drive means for rotating said excavating means around said rodwhile advancing said excavating means along said rod; and means forsupporting said clamping means, excavating means and drive means.
 2. Amachine for excavating a hole as claimed in claim 1, wherein it furthercomprises a tubular casing advanced together with said excavating meansby said drive means; and wherein said excavating means is an earth augerprovided with a screw conveyer received in said casing so as to berotatable around the axis of said casing and having a hole extendingalong the rotary axis so as to receive said rod.
 3. A method forexcavating a hole for communicating between a first space provided inthe ground and a second space apart from the first space, comprisingsteps of:rotating a rod about its axis while advancing the rod from thefirst space to the second space so that said rod may be disposed toextend between the first and the second spaces; and excavating theground by excavating means advanced along said rod from the side of saidsecond space to said first space while utilizing said advanced rod as aguide and maintaining said rod to extend through the first and secondspaces.
 4. A method for excavating a hole claimed in claim 3, whereinsaid rod is guided along a curved path in said first space.
 5. A methodfor excavating a hole claimed in claim 3, wherein said excavating meansis advanced, while maintaining said rod in the relative positionalrelationship between the positions of said rod in the first space and inthe second space.
 6. A method for excavating a hole claimed 3, whereinsaid first space is defined by a sewer pipe embedded in the ground andsaid second space is a space above the ground.
 7. A method forexcavating a hole claimed in claim 3, wherein said first and secondspaces are respectively first and second shafts formed in the ground. 8.An apparatus for excavating a hole for communicating between a firstspace provided in the ground and a second space apart from the firstspace comprising:a rod propelling mechanism for disposing a rod so as toextend between said first and second spaces, said rod propellingmechanism being disposed in said first space and including driving meansfor advancing said rod from said first space to said second space whilerotating said rod around its axis; and an excavating mechanism forexcavating the ground from said second space to said first space whilemaintaining said rod so as to extend between said first and secondspaces and utilizing said rod as a guide; said excavating mechanismhaving: means for clamping a tip end portion of said rod; excavatingmeans disposed so as to extend along said rod; and rotation means foradvancing the excavating means along said rod from said second space tosaid first space while rotating the excavating means around its axis. 9.An apparatus for excavating a hole claimed in claim 8, wherein said rodpropelling mechanism further includes a rod guiding means guiding saidrod so that said rod penetrates a wall member defining said first space.10. An apparatus for excavating a hole claimed in claim 8, wherein saidrod propelling mechanism further includes: rod guiding means placed infront of said driving means for guiding said rod along a curved path;and means for supporting said driving means and said guiding means. 11.An apparatus for excavating a hole claimed in claim 10, wherein saidcurved path is a through hole formed in said guide means so as to permitsaid rod to penetrate same.
 12. An apparatus for excavating a holeclaimed in claim 11, wherein said guide means has a plurality ofbearings and a plurality of spacers disposed alternately along saidcurved path so as to define said curved path.
 13. An apparatus forexcavating a hole claimed in claim 10, wherein said driving meanscomprises:a pair of guides supported by said support means and extendingparallel along said rod from said support means; a slider supported bysaid guides so as to be movable along the guides; a chuck journalled bysaid slider so as to be rotatable about the axis parallel to said guidesand having a through hole extending in the direction of said axis so asto receive said rod; first drive means for rotating said chuck; seconddrive means for moving said sliders back and forth along said guides;and third drive means for operating said chuck so that said chuck clampssaid rod and releases said rod.